Drainage filter system for debris and contaminant removal

Details Drainage filter system for debris and contaminant removal Drainage filter system for debris and contaminant removal

2001-03-16

2003-03-25

Upton, Christopher (Department: 1724)

Liquid purification or separation

Structural installation

Grated inlet surface drain

C210S266000, C210S282000, C210S316000, C210S474000, C210S470000, C404S004000

Reexamination Certificate

active

06537446

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention generally relates to systems and methods for treating water and more specifically relates to systems and methods for separating debris and contaminants from water passing into drains, for example storm drains adjacent paved surfaces, such as along streets in municipalities, parking areas and other similar locations.
Drainage systems collect and direct rainwater and runoff to underground storm sewers to prevent flooding of streets. In some geographic regions, this untreated water is drained directly into the ocean not far from public beaches. Until relatively recently, it was not well appreciated that even residential runoff water can be highly contaminated, and may pose serious threats to the environment and public health.
Typical storm drainage systems include drain inlets placed at margins of streets and roadways and adjacent sidewalks. The drain inlet is commonly equipped with a removable iron grate element that covers at least a portion of the inlet. In addition to providing a safety means, for example to prevent small children and animals from falling into the drain opening, the grate element is designed to prevent some of the relatively larger debris and trash items, such as tree branches, large paper or plastic containers, from entering the storm drain inlet. However, substantial volumes of relatively smaller trash items and debris, including lawn clippings, leaves, empty beverage containers, paper and plastic wrappers and the like, regularly pass into storm drains despite the use of iron grates. These items will eventually cause clogging of the drainage system if not periodically removed. In addition, such iron grates have been found to be ineffective in preventing gradual accumulation of solid materials that enter the drain inlet through open spaces between edges of the drain inlet and a perimeter of the grate element.
Assemblies have been developed for filtering a water flow entering drain system inlets. For example, it is known to place a screen or other porous element below the grate element to collect smaller trash and debris. However, such systems are prone to becoming clogged with debris, thereby obstructing water flow into the storm drain. In addition, such assemblies have not been designed for screening relatively low water flows into the drain inlet. A particularly slow water flow will often bypass the assembly entirely by seeping through unfiltered areas between edges of the assembly and the drain inlet.
Moreover, such periods of low water flow, especially following a relatively long “dry spell” tend to bring highly contaminated runoff water into the drains. This is due to long term accumulation of oils, automobile fluids, dust, dirt, lawn pesticides and other contaminants in the gutter areas of residential and industrial streets.
Devices have been proposed to address the problem of polluted runoff water in drainage systems. For example, U.S. Pat. No. 6,106,707 to Morris et al., which is incorporated herein in its entirety by this specific reference, discloses a modular insert for curb-inlet storm drains for collecting both trash and oil and other hydrocarbons. The device generally comprises a perforated hopper that fits inside a storm drain inlet. The hopper contains fragments of oil absorbent material for entrapping oil in runoff water flowing through the hopper. Although addressing some of the problems associated with present drainage systems, the Morris et al. device and similar conventional devices may be inconvenient and expensive to maintain and do not address other problems that are solved by the present invention.
SUMMARY OF THE INVENTION
New drainage filter apparatus and systems for debris and contaminant removal have been discovered. Such apparatus and systems are straightforward in construction and highly effective in removing particulate matter, debris and contaminants, such as hydrocarbons and other harmful substances from water flowing through a storm drain. The present systems are also easy and inexpensive to maintain and do not hinder or obstruct water flow into drainage systems.
Generally, the present invention is directed to an apparatus for removing debris and contaminants from water passing through a storm drain, for example a storm drain along a city street. The present apparatus typically comprises a debris trap adapted to fit within the storm drain, wherein the debris trap includes a porous element adapted to separate debris from a water flow passing through the storm drain. The apparatus further comprises a frame having a peripheral portion adapted to direct the water flow into the porous element of the debris trap and to prevent bypass of the debris trap during low water flow conditions.
Preferably, the peripheral portion of the frame is sized and shaped to substantially overlap an edge of an inlet opening of the storm drain. In a specific embodiment of the invention, the peripheral portion of the frame comprises an angled iron frame element.
Advantageously, the porous element comprises a sieve element that is removably connected to the frame to facilitate periodic removal and cleaning and/or replacement thereof. The porous element preferably further comprises at least one handle member adapted to facilitate the manual removal of the sieve element from the frame.
The apparatus preferably further comprises a body portion depending from the frame and extending beneath the porous sieve element. The body portion is made of a substantially non-water permeable material, for example a nylon or other polymeric material, and importantly includes an outlet for allowing the water flow to pass into the drain outlet into the sewer system. Furthermore, the body portion and outlet are advantageously structured so that substantially all water passing into the body portion is passed through the outlet before being discharged from the storm drain. A filter member, for example a filtering screen, may be secured across the body portion outlet.
Preferably, the apparatus further comprises a contaminant containment element secured, preferably removably secured, across the body portion outlet. The contaminant containment element comprises a contaminant removal material effective to remove one or more selected contaminants from the water flow as the water flow passes through the contaminant containment element and finally into the storm drain outlet. For example, the contaminant removal material may comprise a material that physically or chemically interacts with contaminants in water, for example dissolved in water, to prevent such contaminants from passing the contaminant containment element and into the sewer system. In one embodiment, the contaminant removal material comprises an oil absorbent material such as polypropylene, though other materials may also be useful depending upon the selected contaminants to be removed, for example, materials which are effective to remove components, microbes, soluble waste products, other water soluble contaminants and the like may be included in the contaminant containment element. Many such materials are known and commercially available. The filtering screen is preferably secured across the body portion outlet downstream of the contaminant containment element.
In one particularly advantageous embodiment of the invention, the porous sieve element comprises a material having a flow rate capacity of at least about 145 gallons per minute per square foot. For example, the material may be a material having a 40 Sieve (U.S. Sieve) porosity. It is further noted that the filtering screen secured across the outlet may comprise the same or similar material.
The present invention is designed to facilitate removal and replacement of the contaminant containment element. After a period of use, the containment element may require replacement in order to assure quality of filtering thereby. For example, the contaminant containment element may be contained by a flexible pocket element defined by the body portion. More specifically, the pocket element is located at least partially abo

Affiliated with

Also associated with

Rating

Drainage filter system for debris and contaminant removal does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Drainage filter system for debris and contaminant removal, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Drainage filter system for debris and contaminant removal will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3082574